96 lines
4.1 KiB
Plaintext
96 lines
4.1 KiB
Plaintext
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=========================================================
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Geant4 - Jet Counter nanodosemeter example
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=========================================================
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README file
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----------------------
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Authors: M. Pietrzak, M. Mietelska, A. Bancer, A. Rucinski and B. Brzozowska
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For any question, please contact the developer:
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marcin.pietrzak@fuw.edu.pl or marcin.pietrzak@ncbj.gov.pl
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This example is provided by the Geant4-DNA collaboration
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Any report or published results obtained using the Geant4-DNA software
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shall cite the following Geant4-DNA collaboration publications:
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[1] Med. Phys. 37 (2010) 4692-4708
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[2] Phys. Med. 31 (2015) 861-874
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In addition, for this example, please cite:
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[3] M. Pietrzak et al 2021 Phys. Med. Biol. 66 225008 (doi: 10.1088/1361-6560/ac33eb).
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----> 0. INTRODUCTION
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The jetcounter example provides a setup for simulation of a typical experiment with the Jet Counter nanodosemeter.
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This example allows the calculation of the ionisation cluster size distribution (ICSD) (the number of ionisations per projectile)
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in a real sized cylindrical interaction volume (IV) of the Jet Counter device.
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The results of each of the simulation are provided in the plain text format.
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Each thread produces its own output file.
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Each row in the output file consist information from a single event, where single primary particle (projectile) was generated.
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Each row contains 4 numbers (columns):
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1. Ionisation cluster size.
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2. Initial energy of the projectile.
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3. Interaction energy of the projectile.
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4. Final energy of the projectile.
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Geometry visualization is available through vis.mac file.
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Script written in Python is provided for visualization of the results.
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----> 1. GEOMETRY SET-UP
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- The height of the interaction volume (IV) is equal to 20 mm and its diameter is equal to 10 mm.
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- The beam axis enters the IV perpendicularly to its axis of rotation, 5 mm from the top.
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- The IV is filled with liquid water material (G4_WATER), but its density is set to 0.45 µg/cm³,
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which corresponds to the nitrogen gas density in real experimental conditions. For details see [3].
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- The beam divergence is restricted by a cylindrical collimator (3 mm in diameter, 23 mm in length) adjacent to the source.
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- There is a wall around the IV in the form of a cylinder opened on both ends. The wall thickness is 0.98 mg/cm² (7 µm).
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- The wall is composed of two layers:
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* outer layer is made of Mylar, 0.96 mg/cm² in thickness;
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* inner layer is made of liquid water (G4_WATER), 0.02 mg/cm² in thickness.
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- There is a silicon (trigger) detector in the form of a thin disk placed behind the IV.
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----> 2. PRIMARY PARTICLES
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If the beam energy is set to any positive value, the beam is mono-energetic with the given energy.
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If the beam energy is set to -1 (default value), the energy spectrum file is used.
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The energy spectrum of the beam is based on experimental data. Its mean energy is 4.6 MeV,
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which is the energy of alpha particles from gold-plated americium (241-Am) source.
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This source is chosen in the primaries.in macro file.
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----> 3. PHYSICS LIST
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The PhysicsList used in this example show how to combine Geant4-DNA physics and standard physics in different regions
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using the G4EmDNAPhysicsActivator.
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1. G4EmDNAPhysics is active in the IV and inner layer of the wall (both made of G4_WATER).
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2. G4EmLivermorePhysics is active in other parts of the setup.
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The G4DNAPhysics_option is chosen in the init_phys.in macro file. Hence, it can be changed without the need of recompilation.
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---->4. SET UP
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Make sure G4LEDATA points to the low energy electromagnetic data files.
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---->5. HOW TO RUN THE EXAMPLE
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For the visualization:
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./jetcounter vis
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For the complete simulation:
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./jetcounter run
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In run.mac macro file will read init_phys.in and primaries.in.
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However, it is recommended to first increase the number of simulated events in the run.mac file to at least 4000.
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To produce figures from simulation results
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(requires numpy and matplotlib Python libraries):
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python3 plot.py
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